Strength-testing apparatus.



J. L.' PERKINS. STRENGTH `'.LESTING APPARATUS.

APPLICATION FILED AUG. 21, 1908.

J.L. PERKINS. STRENGTH TESTING APPARATUS.

v l APPLICATION FILED AUG.21, 1908. 924,579.

'Patented June 8, 1909.

2 SHEETS-SHEET 2.

WfTNEssJmN j ATTORNEY y ments in Strength-Testing UNITED STArnS lPATENT OFFICE.

JOHN L. PERKINS, OF HOLYOKE, MASSACHUSETTS, ASS-IGNORTO B. E. PERKINS AND SON, INCORPORATED, OF HOLYOKE, MASSACHUSETTS, A CORPORATION vOF MASSACHUSETTS.

l STRENGTH-TESTTNG APPARATUS.

Specification of Letters Patent.

Patented June s, 1909.

Application led August 21, 1908. Serial No. 449,672.

To all 'whom it may concern:

Be it known that I, JOHN L. PERKINS, -a

vented certain new and useful Improve- A paratuses, of which the following is a full, cfar, and exact description. 1 v

This invention relates to apparatus for testing the tensile strength of sheet materials, such for linstance as paper; and the apparatus comprises a base or support having a `cylindrical liquid containing bore therein, a piston in the bore and means for endwise moving it against the liquid, another piston in the bore, Ain resistance against the liquid subjected to pressure by the first piston and also endwise movable when a breaking pressure or strain is attained, said second piston having a stem longitudinally extended to the exterior of the bore provided base', a pair of clamps for confining end portions of the sheet material, one `of which is fixed and the other longitudinally movable,

and also oscillatory by reason of having a link-connection withithe aforesaid extended piston stem, and a pressure gage connected with the said bore for indicating the maximum pressureto which the liquid is sub'ected as amedium of transmission of the orce exerted between the' two pistons.

The machine or apparatus is illustrated in the accompanying drawings in which Figure 1 is a substantially central vertical longitudinal section,.the pressure gage or indicator and a portion of the link being shown in front elevation' with parts broken cylindrical bore B of uniform diameter from` end te end therethrough.

a and b represent annular bushing plugs screw'engaged .inthe end ortionswoffthe f bored base; and within the ore arel istons C and D,-provided with cup-leat ers'or h drauliepackings e,'--and arranged in suita `le separation to givespacefor ccupanty between them of a body of liquid, such, for

instance, as glycerin, indicated at a. From a space between the pistons a passage rearwardly and upwardlyleads, andwith.

which the pressure gageE is connected. A portion of the length of the piston .C is made tubular and internally screw' threaded and receives engagement therewithin of r the screw threaded inner portionaof ashaft F which is rotatably fitted through the annular bushing plug a but rendered endwise immovable by the abutment of the shoulders g, g2, which' are provided thereto, against the inner and l'outer ends of the bushing plate. The shaft has at its outer extremity a fixed handwheel G for conveniently turning the shaft F and securing thereby an end- Wise forcing movement of the*v iston C against the body of li uid x. T e other piston D has a 4stem longitudinally extended ,to the exterior of the base inwhieh the bore B is provided at the opposite end from the location of the shaft B`,-its extremity being guided through a circularl apertured' bracket arm h and provided w1 a knob or shoulder i', which b; abutment against the left hand face of the r one()` and is determinativelof ,the normal position of the piston D while lthe endwise abutment at'the right of the piston C against the shoulder 4gy of the. screw shaft F is deterninative of the normal positionof the pist'on J and K representclam ls'for holding the ends of the paper or other s eet strip or cordlike material t0 be tested by a pullings'train thereon. One of the clamps is fixed and the other is movable-.by beingpconnected with the stemH of the piston D. Each clamp comprises a base platform-like member or plate acket lim- "its the movement ofthe piston D toward the 10 and a superimposed movable ripping plate 12 having perforations vertice y therethrough throu hwhich headed studs 13,screw enga ed or otlierwi'se anchored. in the base mem ers, are loosely extended, the heads of such studs limiting the extent lof'separating y movements which the up er clamp plates may have relatively to their fellow members vby reason lof :the interposed and upwardly reactin Isprings 14 accommodated in, counter-sun cavities therefor in the paired plates 10and12, as shown. The skeletonized upper-clamp lates 12. lermit risers or'ear'liigs I15,115,1to leexten ed as inte ral. members of the lower clamp plates consi erably above 30 y ing manifest the feasibility of this apparatus the upper ones, andcam ended levers m `ivote .between and supported by said ear ugs exert each a pressure upon the proxi-y mateupper clam plate to orce' it practically against' the oWer one, to bind the paper, and to securely hold it during the testing operation. e e

rIn the drawings, a strip of paper tor be tested is represented at y 'in all ofV the views. The lower late or lati'orm-like portion of the movab e clamp .is constituted by the end portion ofa linkN, the left hand or farther'end oi' which is apertured and engaged over a portion 17,'which is of reduced diameter of a stud orbar O which is pinned or otherwise affixed to an intermediate ortion of the plunger st em H,-said bar be ow its portion which embraces the piston stem engaging in a slot n in a horizontal member 20` 0f. the aforementioned bracket h whereby the stud Ol is. maintained with double assur. 7

ance in its vertical position Without impediment to its r'eciprocation as an adjunct of the piston and its stem.

The gage or indicator E is, in no material composition, different from ,an ordinary steam gage or gage such ashas been heretoforeused in-other descriptions of paper testing machines, but the same will be herein briely described for the purpose of ,renderas a whole. Y e

The pressure gage comprises a shell or casing p provided with a tubular plug 22 connected with the liquid passage f heretofore referredto as having connection with the portion of i the cylindrical bore B in which the liquid a: is contained; The assage in'the tubular plug is continued .1n a

curved tube 23, the outer or free end of which is closed and which tube is ca able of s ringing under the pressure of liqui forced tlieremto to' a less extremely or sharply curved condition. The age has a graduated face dial 25 over which an index finger or needle 26. is movable, from vthe normal or zeroA positionvariably to the maximum, ac-

A cording to the pressure towhich the liquid needle 26 in extent' pressure to which the liquid issubjected and is subjected bythe forcible movement of the one piston C relatively to the other one D; The needlefis carried on an arbor 27 having a pinion 28 with which meshes 4the sector 30 provided with an upstan ing stud 31. An arm 32 having a hooked end engagesvthe stud 31 and swings the lever and 'moves-the roportionate to .the

gear 29 on an intermediatelydpivoted lever to the strengthening movement of the spring tube 23. Y e

. The .sheet of paper being clamped while the parts of the ap aratus are in their normal positions, an the screw F rotated through the hand wheel G, a pressure will lbe imparted against theliq'uid ata: which will be ,ended lever in the resisted by the clamped paper which restrains the piston D against movement, initially; the pressure to which the liquid is subjected will be absorbed -in the spring tube 23 andV cause a movement around the'faee of the graduatedv dial of the needle 26 up to the time when the pressure becomes so great as to break the paper, whereupon because of such .breakage the iston D and clamp K therewith connectedp will have more or less movement away from the location of the other clamp J. So soon as the papel' becomes severed by the pulling strain imposed thereon, the deflection of the tubular spring 23 not only ceases but suchspring recoils to its normal position shown, leavin the sector osition to w lich it had been swung and t e needle remaining in registry with the graduation on the dial indicating the number of pounds pressure at which the paper had been fractured. Under these conditions the end of the lever carrying the stud 31. will be somewhat above and away from the hook end of the bar 32 which will have returned to its normal position. After an interval sufiicient for the inspection of the gage to perceive under what force a given strip of paper had been broken by the' pulling strain, to which it had been subjectinwardly pushed against an angular arm 35 i of the sector lever and against its spring 36, which 'on the release of the linger pressure for thev restoring of the parts outwardly reactsagain to place the inner end of the stud 34 free and clear from the arm 35 of the sec.- tor leverso as not to in any way impede the next action of the gage.

p By making the clam K as an extremity of the pivoted bar or lin r N, in case the strip of paper is not of uniform width, or is not accurately clamped in the devices J and K,

a rectification will be effected in the line ol" strain on the aper so that it will be vin the truly general ongitudinal line or Umedian vof the strip precluding any tendency which might otherwise exist of a twisting or tearing strain on the strip, but on the other handassuring always a purely pulling or tensile strain.

I claimzscribed, a base orsupport having a cylindrical horizontal' longitudinally extending liquid-containin bore therein, a piston in the bore, a portion of Which'is tubular and internally screw threaded, a shaft, restrained against endwise movement but 4rotatably fitted through an end portion of the base in line with; and screw engaging, said piston,

and havinga hand-wheerfor rotating it,

another piston in the bore, in resistance against t e liquid subjected to pressure by 1. In an apparatus ofthe character dehaving a stem extended beyond the other end fportion of the base, a air of clamps for con 1n end portions of t e sheet material, one of w ich is fixed and the other connected ,with said piston stem and longitudinally movable iny unison therewith, and a pressuregage "connected with the portion of the bore etweengthe pistons. 2. In'jan apparatus `of the'cha1acter described, .a base or. support having a horizontal c lindrical bore extending from end to end t erethrou h, annular screw plugs'engaged in each en of the bore, a piston Within one end ortionof the bore, a portion of which is tu'bu ar and internally screw threaded, a shaft, `a portion of' which is rotatably fitted in one of said annular screw plugs, the inner end portion thereof being threaded and screw engaging said piston, and having shoulders' in engagement against-'the inner and out body of liquid in the intermediate portion of the bfore between said pistons and apressure gage connected with the'liquid containing portion of the bore.

3. In an apparatus of the character described, a base or support having'a flat topv and havinga cylindrlcal longitudinally eX- tending liquid containing bore therein, a piston in the bore land means for endwise moving it,'anothe'r piston in the bore having a stem longitudinally extended to the exterior ofthe base, a clamp in ,a fixed position on the top ofthe base comprising a base plate anda separable superim osed plate, s rings oper- 'atlve to force the p ate apart an a c am'lever for forcing Vthe one plate againstthe other, another clamp slidably sulpported on the top base comprising a basep ate constituted by an extremity of a bar or link having a piv. otal connection with the'stem of the'second named pistonand having `a superimposed plate with interposed separating springs and t Witnesses:

a cam lever for crowding the clamp members together, and a pressure gage connected with the portion of the bore between the pistons.

4. In an apparatus-of the character described, a base or main elongated horizontal support having a cylindrical bore therethrough, se arated pistons in said bore with a body of'v iquid therebetween, one of said pistons having' a stem extending endwise beyoud the base, a bracket at the end of the ase comprising a horizontal member with a longitudinal upwardly opening groove thereinand a vertical member through which said stem lays, a knob at the end of the stem outsidldv of the bracket, a bar embracing and secured to the stem having a depending member slidably (guided in said groove and having an u stan ing stud, a bar having one .end pivotaly engaged with said stud and having its other extremity supported on the flat top of the base and comprised in a movlable paper clamp, another paper clam in al xed position at a furtherportion ont e to' of the base, a-pressure gage connected wit the liquid containing portion of the said bore, and meansv for endwise moving the piston which is opposed to the said stem provided 5. In an apparatus of the character vdescribed, the combination with a base having said piston stem, a pressure gage comprising a tubular plug connected with said conduit, and a body of liquid in the bore between the pistons 'and communicating through said conduit with the ga e.

Signed by' me at olyoke, Mass., in presence of two subscribing witnesses.

JOHN L. PERKINs F.` S. KEENs, WM. H. BOND. 

